public class switchcase {
    public static void main(String[] args) {
        char c='d';
        switch (c)
        {
            case 'a':
                System.out.println("优");
                break;
            case 'b':
                System.out.println("良");
                break;
            case 'c':
                System.out.println("及格");
                break;
            case  'd':
                System.out.println("不及格");
                break;
            default:
                break;
        }
    }
}
